Posted on September 6th, 2017 by Adithya Rajendran

Things have changed since the glory days of Yuri Gagarin when we first reached for the stars. Now, it is easier than ever to get involved in a space mission.

The High-Altitude Ballooning project at BLUEsat UNSW brings together passionate students from a wide range of degrees to build, test and launch equipment to altitudes over 30km.

Our most recent mission was on the 5th of August, where we sent our custom-built scientific research payload up 33km to gather data on the atmosphere and capture video of the ascent.

So, you’re probably thinking to yourself, how can I do this from home?

Objectives

Do you want to take stunning pictures of the curvature of the earth? Perhaps take a photo of your teddy bear against the backdrop of space?

Our main objective was to study the atmosphere to gain knowledge for future missions. This involved sensors, an onboard computer, and code to log data. We used a Raspberry Pi for computing, with an accelerometer, gyroscope, magnetometer, barometer, temperature probes and humidity sensor recording data to an SD card.

We also captured video and photos with two cameras mounted on our payload.

Tracking

Without knowing where your payload is during flight, you have just launched a glorified party balloon. We used 3 discrete self-contained systems to track our flight, pictured below.

The SPOT GPS Tracker simply transmits and uploads coordinates to a website, where we can view location updates on a map. An APRS radio device, the yellow box, transmits GPS coordinates over amateur radio bands which are uploaded to an online network. The third device is a short-range radio beacon which plays a continuous tune over radio frequencies, allowing us to pinpoint the landing area.

Tracking equipment

Separation

Typically, a mission is ended when the balloon bursts, but if you are feeling fancy, you can build a device that can remotely cut down your payload. We have developed a mechanism that runs a current through a piece of nichrome wire, which is wrapped around the rope connecting the balloon to the payload. An on-board radio receiver decodes a termination signal which we can send from the ground, causing the nichrome to heat up and sever the rope.

Approval

Before you can send anything into the air, you must seek approval from CASA, the Civil Aviation Safety Authority. You will also need to perform predictions of your flight using online prediction software, such as that found at HabHub, which will allow you to visualise the estimated flight path and burst altitude based on weather forecasts. The figure below shows a predicted trajectory for our launch.

Prediction of flight trajectory from Muswellbrook, NSW

Logistics

You now need to hire a tank of helium and drive all your equipment out to your launch site. Make sure you take a toolbox and spare parts with you for any last minute adjustments.

Final preparations

The Launch

Once you have inflated the balloon with enough helium to attain the desired lift and attached your payload, you are ready for launch. Perform a final flight prediction, check your on-board systems, turn on your cameras and cross your fingers!

It’s time to let go…

Watch the promotional video of our launch below:

Watch our student-led group BLUEsat launch a high-altitude balloon! Spectacular footage as it reaches an altitude of 33,000 m…. 3 times higher than a commercial aircraft.